20 hours of TV a week almost halves sperm count

Contact: Stephanie Burns sburns@bmjgroup.com 44-020-738-36920 BMJ-British Medical Journal

But 15 or more hours a week of moderate to vigorous exercise improves it

Healthy young men who watch TV for more than 20 hours a week have almost half the sperm count of men who watch very little TV, indicates a study published online in the British Journal of Sports Medicine.

Conversely, men who do 15 or more hours of moderate to vigorous exercise every week have sperm counts that are 73% higher than those who exercise little, the findings show.

Semen quality seems to have deteriorated over the past few decades, although it’s not clear why, say the authors.

To find out if an increasingly sedentary lifestyle might be a contributory factor, they analysed the semen quality of 189 men between the ages of 18 to 22 in 2009-10, all of whom were from Rochester in New York State, USA.

The men were asked about the quantity and intensity of weekly exercise they had had over the preceding three months, and how much time they spent watching television, DVDs, or videos over the same period.

And they were asked about factors that might affect sperm quality, including medical or reproductive health problems, diet, stress levels, and smoking.

Over half the men were within the normal range for weight for their height, and three out of four were non-smokers. The prevalence of reproductive health problems was low.

The amount of moderate to vigorous physical activity taken every week ranged from 5 to 14 hours, while weekly TV screen time varied from 4 to 20 hours. Men who were more physically active tended to have a healthier diet than those who watched a lot of TV every week.

The analysis showed that those who were the most physically active—15+ hours a week—had a 73% higher sperm count than the least physically active. Exercise did not affect sperm motility, shape, or sample volume.

When analysed by exercise intensity, the results showed that light physical exercise made no difference to the sperm count, no matter how frequent it was.

TV viewing had the opposite effect. Those who watched the most—20 or more hours a week—had a sperm count that was 44% lower than those who watched the least. It had no impact on sperm motility, shape, or sample volume.

And unlike smoking or weight, the amount of TV viewing seemed to counteract the beneficial effects of exercise, although this may be a chance finding, say the authors.

The authors caution that a reduced sperm count does not necessarily curb a man’s fertility or his chances of being able to father a child, but the findings do suggest that a more physically active lifestyle may improve semen quality.

The type of exercise might also be important, say the authors, who conclude: “Future studies should also evaluate the extent to which different exercise types affect semen quality as previous studies suggest that there might be opposing effects of different types of activity on semen characteristics.”

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[Physical activity and television watching in relation to semen quality in young men Online First doi 10.1136/bjsports-2012-091644]

Semen quality of young men in south-east Spain down by 38 percent in the last decade

Contact: SINC info@agenciasinc.es 34-914-251-820 FECYT – Spanish Foundation for Science and Technology

The first comparative study on the evolution of sperm quality in young Spanish men over ten years, headed by researchers at the University of Murcia, reveals that spermatozoid concentration in men between 18 and 23 years in the regions of Murcia and Almeria has dropped by an annual average of 2%.

The suspicion that the semen of Spanish men is losing quality now takes force in the case of young men from Murcia and Almeria.

The ‘Andrology‘ journal has published a multidisciplinary and international study, headed by the Department of Preventative Medicine and Public Health of the University of Murcia (UMU), which demonstrates that “total sperm count and concentration has declined amongst young men in the south-east of Spain in the last decade.” More specifically, the decrease amounts to 38%.

The lead researcher, Alberto Torres Cantero, explains to SINC that the study involved “comparing the results obtained by the Medical Research Centre of the University of Granada from the semen of 273 men from Almeria between 18 and 23 years, collected between 2001 and 2002, with those samples collected ten years later by 215 undergraduates from Murcia, all the while ensuring that both sample groups had the same age range and similar characteristics.”

The analysis shows that the number of spermatozoids is significantly lower in the subjects from Murcia compared to the participants from Almeria. Average concentration goes from 72 million spermatozoids per millilitre in 2011 to 52 million/ml in 2011, according to Torres Cantero, professor of Preventative Medicine and Public Health at UMU.

Another relevant result is that “40% of those university students analysed in Murcia suffered from alterations in at least one semen parameter (morphology, mobility). Furthermore, all sperm indicators are below the norm in 15% of the sample,” states Jaime Mendiola, professor at the UMU and first signatory of the study.

Clinic trails are needed

“Before there were no well performed studies to detect a change in sperm quality in Spain,” explains Torres. Its main limitation is that it only makes reference to one geographic area and cannot be extrapolated: “We do not know if the same has occurred in other parts of Spain,” outlines the researcher. There is little likelihood that the study will be carried out in other regions “because there are no similar semen quality studies in the young and healthy population.”

Nonetheless, the fact that semen has worsened does not necessarily mean that the number of infertile men has increased. As Torres clarifies, this study measures semen quality and not fertility, “for which specific criteria established by the WHO are used.”

Despite this, Mendiola feels that these data are worrying because “it has been verified in recognised studies that a concentration lower than 40 million/ml makes conception more difficult. If the rate of loss we have outlines continues, with an average decline in quality of 2% per year, the sperm of young men could reach this danger level of 40 million/ml in a very short space of time.”

For this reason, the authors stress the urgency to promote “clinical trails that identify effective prevention actions for counteracting this negative trend via lifestyle changes.”

“We believe that some prevention actions involving lifestyle improvements, such as a healthier diet, could increase sperm quality,” outlines Alberto Torres. “But we still lack rigorous scientific information to propose them neither in the clinical field nor at a population level. If we could identify those actions, we could improve sperm quality.”

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This study enjoyed the participation of the Department of Preventative Medicine of New York’s Mount Sinai Hospital, the Reproduction Department of the University of Copenhagen, the Spanish universities of Granada and Miguel Hernández (Elche) and Dexeus and Fertilidad Roca clinics in Murcia. It was financed by the Fundación Séneca – the Science and Technology Agency of the Region of Murcia – and the Health Research Fund (FIS) of the Carlos III Institute.

 

Contact:

Alberto Torres Cantero investigador principal catedrático de Medicina Preventiva y Salud Pública de la Universidad de Murcia amtorres@um.es teléfono: 868 88 46 57

Reference:

http://onlinelibrary.wiley.com/doi/10.1111/j.2047-2927.2012.00058.x/abstract;jsessionid=F1B8DE0AD83F78A0DFAC4F2BF4ADF7C2

Scientists warn of sperm count crisis : “serious public health warning”

Biggest-ever study confirms drastic decline in male reproductive health

Jeremy Laurance

Wednesday, 5 December 2012

The reproductive health of the average male is in sharp decline, the world’s largest study of the quality and concentration of sperm has found.

Between 1989 and 2005, average sperm counts fell by a third in the study of 26,000 men, increasing their risk of infertility. The amount of healthy sperm was also reduced, by a similar proportion.

The findings confirm research over the past 20 years that has shown sperm counts declining in many countries across the world. Reasons ranging from tight underwear to toxins in the environment have been advanced to explain the fall, but still no definitive cause has been found.

The decline occurred progressively throughout the 17-year period, suggesting that it could be continuing.

The latest research was conducted in France but British experts say it has global implications. The scientists said the results constituted a “serious public health warning” and that the link with the environment “particularly needs to be determined”.

The worldwide fall in sperm counts has been accompanied by a rise in testicular cancer – rates have doubled in the last 30 years – and in other male sexual disorders such as undescended testes, which are indicative of a “worrying pattern”, scientists say.

There is an urgent need to establish the causes so measures can be taken to prevent further damage, they add.

Richard Sharpe, professor of reproductive health at the University of Edinburgh and an international expert on toxins in the environment, said the study was “hugely impressive” and answered sceptics who doubted whether the global decline was real.

“Now, there can be little doubt that it is real, so it is a time for action. Something in our modern lifestyle, diet or environment is causing this and it is getting progressively worse. We still do not know which are the most important factors but the most likely are … a high-fat diet and environmental chemical exposures.”

Researchers from the Institut de Veille Sanitaire, St Maurice, used data from 126 fertility clinics in France which had collected semen samples from the male partners of women with blocked or missing fallopian tubes. The men, whose average age was 35, did not have fertility problems of their own and were therefore considered representative of the general male population.

The results, reported in the journal Human Reproduction, showed the concentration of sperm per millilitre of semen declined progressively by 1.9 per cent a year throughout the 17 years – from 73.6 million sperm per millilitre in 1989 to 49.9 million/ml in 2005. The proportion of normally formed sperm also decreased by 33.4 per cent over the same period.

Although the average sperm count of the men was well above the threshold definition of male infertility – which is 15 million/ml – it was below the World Health Organisation threshold of 55 million/ml which is thought to lengthen the time to conceive. Other European studies have shown that one in five young men has a sperm count low enough to cause problems conceiving.

Combined with other social trends, such as delayed childbearing which reduces female fertility, the decline in sperm counts could signal a crisis for couples hoping for a family.

Sperm count: How to boost it

1. Wear loose underwear – to make healthy sperm the testicles need to be below body temperature.

2. Eat food low in saturated fat.

3. Avoid smoking, drinking, using drugs and becoming obese.

4. Reduce exposure to industrial chemicals such as those used in making plastics – they can mimic the female hormone oestrogen countering male hormones.

5. Protect women in pregnancy – there is growing evidence that falling sperm counts may stem from effects in the womb.

6. Avoid anti-depressants – in rare cases they can cut sperm counts.

 

http://www.independent.co.uk/news/science/scientists-warn-of-sperm-count-crisis-8382449.html?printService=print

Male painters exposed to fertility damaging chemicals: glycol ether

Contact: Lindsey Bird
l.bird@sheffield.ac.uk
01-142-225-338
University of Sheffield

Men working as painters and decorators who are exposed to glycol ethers are more likely to have poor semen quality, according to research carried out by scientists from the Universities of Sheffield and Manchester.

The findings from the research, which have been published in the BMJ journal Occupational Environmental Medicine, show that men who work with solvents such as glycol ether have a 2.5 fold increased risk of having a low motile sperm count compared to men with low exposure. Glycol ethers are widely used in many products including water-based paints – a product used by many painters and decorators.

Sperm motility is an important factor in the fertility of men and the concentration of motile sperm per ejaculate has shown to be linked with conception. However, the size and shape of sperm (morphology) and the quality of sperm DNA are also important factors that may be affected by chemical exposure.

The findings are a result of a major collaborative UK study to determine the occupational risks of male infertility through chemical exposure in the workplace. The study, undertaken in 14 fertility clinics in 11 cities across the UK, examined the working lives of 2,118 men.

The researchers however did conclude that, apart from glycol ether, there are currently few workplace chemical threats to male fertility.

In additional to chemical exposure, the study looked at other non-chemical factors in the men’s lifestyle. The researchers discovered that men who had undergone previous surgery to the testicles or who undertook manual work were more likely to have low motile sperm counts, whereas men who drank alcohol regularly or wore boxer shorts were more likely to have better semen quality.

Dr. Andy Povey, senior lecturer in Molecular Epidemiology at the University of Manchester, said: “We know that certain glycol ethers can affect male fertility and the use of these has reduced over the past two decades. However our results suggest that they are still a workplace hazard and that further work is needed to reduce such exposure.”

Dr Allan Pacey, senior lecturer in Andrology at the University of Sheffield, added: “Infertile men are often concerned about whether chemicals they are exposed to in the workplace are harming their fertility. Therefore it is reassuring to know that on the whole the risk seems to be quite low.”

 

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Notes for editors:

The study was funded by the UK Health and Safety Executive, the UK Department of Environment, Transport and the Regions, the UK Department of Health and the European Chemical Industry Council.